Method for preserving high-moisture beer lees as animal feed
By using a three-layer composite fermentation bag and a step-by-step filling pressure gradient technology, the problem of easy spoilage of high-humidity brewer's grains has been solved, achieving low-cost, high-efficiency preservation and nutrient retention, which is suitable for a stable supply of animal feed.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XINJIANG NONGKEN TIANKUN AGRICULTURE & ANIMAL HUSBANDRY CO LTD
- Filing Date
- 2026-02-06
- Publication Date
- 2026-06-09
AI Technical Summary
High-moisture brewer's grains are prone to spoilage due to their high moisture content. Traditional storage methods are costly and result in significant nutrient loss, making effective storage and transportation difficult.
A three-layer composite fermentation bag is used for step-by-step filling and pressure gradient generation. It combines a microporous water-permeable membrane, a middle layer of bacterial agent carrier grid and an oxygen barrier layer. Through fermentation gas pressure exhaust and oxygen barrier, it matures in zones and applies pressure to form a stable antibacterial structure. Finally, mechanical pressing locks in the water activity.
It significantly reduces costs, achieves preservation of high-moisture brewer's grains, maintains nutritional components, extends the storage period at room temperature, is easy to operate and requires no continuous monitoring, and is suitable for stable supply in the livestock feed supply chain.
Smart Images
Figure CN122162872A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of animal feed technology, specifically to a method for preserving high-moisture brewer's grains in animal feed. Background Technology
[0002] High-moisture brewer's grains (HQG) are a major byproduct of the beer industry. They are solid residues left after fermentation during the brewing process, with a high moisture content, typically between 70% and 85%, hence the term "high-moisture." Their main components include incompletely decomposed malt, the husks of grains such as rice, residual protein, crude fat, crude fiber, various vitamins, and minerals. This feed has some nutritional value, being relatively rich in protein with a balanced amino acid composition, providing essential nutrients for animals. It also contains some unknown growth factors beneficial to animal growth and health. However, due to its high moisture content, HQG is prone to spoilage and is difficult to store and transport. It usually requires timely processing and utilization. Common methods include direct feeding to ruminants such as cattle and sheep, or adding it to other animal feeds after drying and fermentation.
[0003] With the continuous development of the beer industry, brewer's grains, as one of the main wastes generated during the brewing process, pose a significant environmental pollution risk if discarded. Their rational utilization has become a focus of attention within the industry. Brewer's grains are rich in nutrients, including protein, cellulose, and minerals, and have high reuse value. However, due to their high moisture content (usually exceeding 75%), they are prone to mold and spoilage, posing considerable challenges to their storage, transportation, and subsequent processing. Traditional storage methods, such as drying, dehydration, and cellaring, reduce the moisture content to below 60%, but these methods are costly, result in significant nutrient loss, and do not achieve optimal fattening effects when fed to livestock. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides a method for preserving high-humidity brewer's grains in animal feed, which solves the problems of high cost and nutrient loss associated with existing storage methods.
[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for preserving high-moisture brewer's grains in animal feed, specifically comprising the following steps: S1. Pre-isolation layer laying A three-layer composite fermentation bag is used, including an inner microporous water-permeable membrane, a middle layer of bacterial agent carrier grid, and an outer oxygen barrier layer, in which the solid dormant composite bacterial agent is pre-encapsulated in the middle layer of bacterial agent carrier grid; S2. Step-by-step filling and pressure gradient generation Fill the bottom of the fermentation bag with fresh beer lees with a moisture content of 75% or more by mass, compact it to a bulk density of 700 kg / m³, let it stand for 30 minutes to allow the bottom layer of moisture to soak in and activate the middle layer of microbial agents, fill the top layer of the fermentation bag with beer lees with a moisture content of 70% to 72% by mass, cover it with the middle layer of mesh and compact it to the same bulk density. S3. One-way differential pressure exhaust The filled fermentation bags are placed on a 15-degree inclined flow guide frame with the bag opening facing upwards and connected to a U-shaped water seal pipe to achieve dynamic exhaust and oxygen barrier using the fermentation gas pressure. S4. Zone Maturation and Barrier Switching The main fermentation period is 1 to 5 days, maintaining an ambient temperature of 25 to 35 degrees Celsius. At the end of the 5th day, physically close the bag channel below the middle mesh, remove the U-shaped tube and heat-seal the bag opening, then transfer the fermentation bag to an environment of 15 to 20 degrees Celsius and let it mature with the bottom facing down. S5. In-situ solidification and nutrient locking When the pH value is detected to be ≤4.2 and there is no mold, place the fermentation bag under a controllable pressure plate and apply a pressure of 0.2 MPa for 24 hours to make the water activity ≤0.85.
[0006] Preferably, in step S1, the inner microporous permeable membrane has a pore size ≤ 5 micrometers, the middle bacterial agent carrier mesh is a biodegradable cellulose mesh, and the outer oxygen barrier layer is a biaxially oriented polypropylene membrane.
[0007] Preferably, in step S2, the bottom layer of beer lees accounts for 40% of the total volume, and the top layer of beer lees accounts for 60%.
[0008] Preferably, in step S3, the water level difference in the U-shaped water seal pipe controls the air pressure inside the bag to be 0.005 to 0.01 MPa.
[0009] Preferably, the physical clamping in step S4 uses a polypropylene snap-on clamp, with the clamping position located 5 cm below the middle mesh.
[0010] Preferably, the pressing operation in step S5 is performed under conditions where the ambient temperature is below 20 degrees Celsius.
[0011] Preferably, the compound microbial agent includes Lactobacillus plantarum, Saccharomyces cerevisiae, and Bacillus subtilis, with a mass ratio of 5:3:2.
[0012] The special fermentation bag of the method includes a microporous water-permeable membrane, a microbial agent carrier grid and an oxygen barrier layer, which are sequentially composited from the inside to the outside. The microbial agent carrier grid contains a solid composite microbial agent. The bottom of the bag is provided with a flow guide groove, and the bag opening is provided with a heat sealing tape and a U-shaped tube interface. The side wall of the bag is marked with double-layer filling scale lines, corresponding to the 40% and 100% volume positions respectively.
[0013] This invention provides a method for preserving high-moisture brewer's grains in animal feed. It has the following beneficial effects: This invention provides a method for preserving high-humidity brewer's grains in animal feed. This technology significantly reduces costs by replacing drying and vacuum treatment with physical methods, thereby reducing energy consumption and equipment requirements. In terms of preservation, it ensures that microorganisms quickly establish an antibacterial environment in high humidity, and the zoned maturation technology completely blocks mold growth. Terminal mechanical pressing forms a stable, anti-corrosion structure. The entire process overcomes the limitations of insufficient uniformity in traditional fermentation, achieving a high proportion of crude protein and cellulose preservation, significantly extending the storage period at room temperature. The operation process is highly standardized, and workers can master the application of all tools with simple training, eliminating the need for continuous monitoring and adjustment. Ultimately, it achieves a perfect balance between nutritional preservation and safe storage, providing an innovative solution for balanced supply across seasons in the livestock feed supply chain and constructing a new path for low-investment, highly stable wet grains treatment technology. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation
[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0016] like Figure 1 As shown, this embodiment of the invention provides a method for preserving high-moisture brewer's grains in animal feed, specifically including the following steps: S1. Pre-isolation layer laying A three-layer composite fermentation bag is used, including an inner microporous water-permeable membrane, a middle layer of bacterial agent carrier grid, and an outer oxygen barrier layer, in which the solid dormant composite bacterial agent is pre-encapsulated in the middle layer of bacterial agent carrier grid; S2. Step-by-step filling and pressure gradient generation Fill the bottom of the fermentation bag with fresh beer lees with a moisture content of 75% or more by mass, compact it to a bulk density of 700 kg / m³, let it stand for 30 minutes to allow the bottom layer of moisture to soak in and activate the middle layer of microbial agents, fill the top layer of the fermentation bag with beer lees with a moisture content of 70% to 72% by mass, cover it with the middle layer of mesh and compact it to the same bulk density. S3. One-way differential pressure exhaust The filled fermentation bags are placed on a 15-degree inclined flow guide frame with the bag opening facing upwards and connected to a U-shaped water seal pipe to achieve dynamic exhaust and oxygen barrier using the fermentation gas pressure. S4. Zone Maturation and Barrier Switching The main fermentation period is 1 to 5 days, maintaining an ambient temperature of 25 to 35 degrees Celsius. At the end of the 5th day, physically close the bag channel below the middle mesh, remove the U-shaped tube and heat-seal the bag opening, then transfer the fermentation bag to an environment of 15 to 20 degrees Celsius and let it mature with the bottom facing down. S5. In-situ solidification and nutrient locking When the pH value is detected to be ≤4.2 and there is no mold, place the fermentation bag under a controllable pressure plate and apply a pressure of 0.2 MPa for 24 hours to make the water activity ≤0.85.
[0017] In step S1, the inner microporous permeable membrane has a pore size ≤ 5 micrometers, the middle layer of microbial agent carrier mesh is a biodegradable cellulose mesh, and the outer oxygen barrier layer is a biaxially oriented polypropylene membrane. In step S2, the bottom layer of brewer's grains accounts for 40% of the filling volume, and the top layer accounts for 60%. In step S3, the water level difference in the U-shaped water seal pipe controls the air pressure inside the bag to be 0.005 to 0.01 MPa. In step S4, the physical clamping uses a polypropylene snap-lock clamp, with the clamping position located 5 cm below the middle layer mesh. The pressing operation in step S5 is performed under conditions where the ambient temperature is below 20 degrees Celsius. The compound microbial agent includes Lactobacillus plantarum, Saccharomyces cerevisiae, and Bacillus subtilis, with a mass ratio of 5:3:2.
[0018] The method's dedicated fermentation bag includes a microporous permeable membrane, a microbial agent carrier grid, and an oxygen barrier layer, which are sequentially composited from the inside out. The microbial agent carrier grid contains a solid composite microbial agent. The bottom of the bag is equipped with a flow guide groove, and the bag opening is equipped with a heat-sealing tape and a U-shaped tube interface. The side wall of the bag is marked with double-layer filling scale lines, corresponding to the 40% and 100% volume positions, respectively.
[0019] Table 1: Verification of mold inhibition effect ; As shown in Table 1, the U-shaped water seal keeps the oxygen concentration inside the bag below 0.5% throughout the process (tested in GB / T6439-2007), physically blocking the aerobic environment required by mold.
[0020] Table 2: Comparison of nutrient retention rates (%) ; As shown in Table 2, the stratified activation agent reduced the pH to 4.3 within 24 hours (measured by a pH meter), effectively inhibiting protease decomposition; terminal pressing resulted in an intracellular water exudation rate of 63%, slowing down nutrient loss.
[0021] Table 3: Changes in Key Indicators During Storage Period ; As shown in Table 3, after the partitioning is closed, an anaerobic core zone is formed at the bottom (Eh<-150mV), and the aerobic bacteria in the upper layer undergo autolysis due to lack of oxygen, thus achieving a self-sterilization effect.
[0022] This technology overcomes the technical bottleneck of preserving high-humidity brewer's grains through an innovative physical-biological synergistic mechanism. Its core advantages lie in the construction of three key technology systems: moisture gradient-driven fermentation, self-balancing gas pressure control, and switchable physical barriers. Economically, it achieves a zero-drying process, low cost per ton, directly reducing energy consumption and saving on equipment investment. In terms of preservation effect, it achieves four-fold protection: moisture gradient activation rapidly establishes an acidic environment within 24 hours, with the pH value stabilizing below 4.2; a gravity-hydraulic U-tube maintains a slight positive pressure of 0.005 to 0.01 MPa, continuously expelling carbon dioxide and physically blocking oxygen backflow; a middle-layer mesh effectively isolates cross-contamination of byproducts from different fermentation stages; and terminal 0.2 MPa mechanical pressing permanently reduces water activity to below 0.85, forming a dense antibacterial structure. Ultimately, this results in high crude protein retention, low mold rate, long shelf life at room temperature, and cellulose degradation rate controlled below 40% for fresh brewer's grains containing water, fully supporting cross-seasonal production and sales scheduling needs. The process relies entirely on the interaction of physical rules and biological processes, requiring no electronic sensors or intelligent control systems. Operators only need to master the basic tool usage guidelines to implement it.
[0023] Detailed implementation process of this technology: The first step involves setting up a pre-isolation layer: Prepare a three-layer fermentation bag. The inner layer is a water-permeable membrane with a pore size ≤ 5 micrometers; the middle layer contains a cellulose mesh with a solid dormant compound microbial agent; and the outer layer is covered with an oxygen-barrier polypropylene membrane. The second step is layered filling. First, pour fresh brewer's grains with a moisture content ≥ 75% into the bottom layer of the bag, compact it to a bulk density of 700 kg / m³, and let it stand for 30 minutes to allow the moisture in the bottom layer to seep upwards and activate the middle layer of microbial agent. Then, pour brewer's grains with a moisture content of 70%–72% over the middle layer mesh into the top layer, compacting it to the same standard. The third step is to initiate fermentation and degassing. Place the bag on a 15-degree inclined flow guide frame, with the bag opening facing upwards, and connect a water injection U-shaped pipe. The fermentation pressure drives liquid level fluctuations to achieve self-degassing and oxygen barrier. The fourth step involves stage management. During the main fermentation period of 1-5 days, maintain an environment of 25-35 degrees Celsius. At the end of the 5th day, use polypropylene clips to seal the bag channel 5 cm below the inoculant grid for partitioning and isolation. After removing the U-shaped tube, heat-seal the bag opening and transfer it to an environment of 15-20 degrees Celsius with the bottom layer facing down for static maturation. The fifth step involves endpoint control. When the pH value is ≤4.2 and there are no mold spots, apply a pressure of 0.2 MPa to the entire bag at an environment below 20 degrees Celsius for 24 hours, ultimately reducing the water activity to below 0.85 to complete preservation. The finished product can then be directly stacked for storage or transportation. This process requires ensuring that the bottom layer accounts for 40% of the filling volume, the top layer accounts for 60%, and the inoculant composition is carried out according to the ratio of Lactobacillus plantarum: Saccharomyces cerevisiae: Bacillus subtilis in 5:3:2.
[0024] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A method for preserving high-moisture brewer's grains in animal feed, characterized in that, Specifically, the following steps are included: S1. Pre-isolation layer laying A three-layer composite fermentation bag is used, including an inner microporous water-permeable membrane, a middle layer of bacterial agent carrier grid, and an outer oxygen barrier layer, in which the solid dormant composite bacterial agent is pre-encapsulated in the middle layer of bacterial agent carrier grid; S2. Step-by-step filling and pressure gradient generation Fill the bottom of the fermentation bag with fresh beer lees with a moisture content of 75% or more by mass, compact it to a bulk density of 700 kg / m³, let it stand for 30 minutes to allow the bottom layer of moisture to soak in and activate the middle layer of microbial agents, fill the top layer of the fermentation bag with beer lees with a moisture content of 70% to 72% by mass, cover it with the middle layer of mesh and compact it to the same bulk density. S3. One-way differential pressure exhaust The filled fermentation bags are placed on a 15-degree inclined flow guide frame with the bag opening facing upwards and connected to a U-shaped water seal pipe to achieve dynamic exhaust and oxygen barrier using the fermentation gas pressure. S4. Zone Maturation and Barrier Switching The main fermentation period is 1 to 5 days, maintaining an ambient temperature of 25 to 35 degrees Celsius. At the end of the 5th day, physically close the bag channel below the middle mesh, remove the U-shaped tube and heat-seal the bag opening, then transfer the fermentation bag to an environment of 15 to 20 degrees Celsius and let it mature with the bottom facing down. S5. In-situ solidification and nutrient locking When the pH value is detected to be ≤4.2 and there is no mold, place the fermentation bag under a controllable pressure plate and apply a pressure of 0.2 MPa for 24 hours to make the water activity ≤0.
85.
2. The method for preserving high-moisture brewer's grains in animal feed according to claim 1, characterized in that: In step S1, the inner microporous permeable membrane has a pore size of ≤5 micrometers, the middle bacterial agent carrier mesh is a biodegradable cellulose mesh, and the outer oxygen barrier layer is a biaxially oriented polypropylene membrane.
3. The method for preserving high-moisture brewer's grains in animal feed according to claim 1, characterized in that: In step S2, the bottom layer of beer lees accounts for 40% of the total volume, and the top layer of beer lees accounts for 60%.
4. The method for preserving high-moisture brewer's grains in animal feed according to claim 1, characterized in that: In step S3, the water level difference in the U-shaped water seal pipe controls the air pressure inside the bag to be 0.005 to 0.01 MPa.
5. The method for preserving high-moisture brewer's grains in animal feed according to claim 1, characterized in that: The physical clamping in step S4 uses a polypropylene snap-on clamp, with the clamping position located 5 cm below the middle layer mesh.
6. The method for preserving high-moisture brewer's grains in animal feed according to claim 1, characterized in that: The pressing operation in step S5 is performed under conditions where the ambient temperature is below 20 degrees Celsius.
7. The method for preserving high-moisture brewer's grains in animal feed according to claim 1, characterized in that: The compound microbial agent includes Lactobacillus plantarum, Saccharomyces cerevisiae, and Bacillus subtilis, with a mass ratio of 5:3:
2.
8. The special fermentation bag according to any one of claims 1-7, characterized in that: It includes a microporous water-permeable membrane, a microbial agent carrier grid, and an oxygen barrier layer, which are sequentially composited from the inside out. The microbial agent carrier grid contains a solid composite microbial agent. The bottom of the bag is provided with a flow channel, and the bag opening is provided with a heat-sealing tape and a U-shaped tube interface. The side wall of the bag is marked with double-layer filling scale lines, corresponding to the 40% and 100% volume positions respectively.